$OpenBSD: patch-acinclude_m4,v 1.2 2012/05/03 06:06:59 ajacoutot Exp $
--- acinclude.m4.orig	Sat Nov 19 11:50:27 2011
+++ acinclude.m4	Sun Apr 29 00:25:46 2012
@@ -284,6 +284,38 @@ fi
 
 dnl -----------------------------------------------------------------------
 
+dnl TC_CHECK_SNDIO([ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]])
+dnl Test for sndio headers
+dnl
+AC_DEFUN([TC_CHECK_SNDIO],
+[
+AC_MSG_CHECKING([whether sndio support is requested])
+AC_ARG_ENABLE(sndio,
+  AC_HELP_STRING([--enable-sndio],
+    [enable sndio support (no)]),
+  [case "${enableval}" in
+    yes) ;;
+    no)  ;;
+    *) AC_MSG_ERROR(bad value ${enableval} for --enable-sndio) ;;
+  esac],
+  [enable_sndio=no])
+AC_MSG_RESULT($enable_sndio)
+
+have_sndio="no"
+if test x"$enable_sndio" = x"yes" ; then
+  AC_CHECK_HEADERS([sndio.h], [have_sndio="yes"])
+
+  if test x"$have_sndio" = x"yes" ; then
+    have_sndio="yes"
+    ifelse([$1], , :, [$1])
+  else
+    AC_MSG_ERROR([sndio is requested, but cannot find headers])
+  fi
+fi
+])
+
+dnl -----------------------------------------------------------------------
+
 dnl TC_CHECK_OSS([ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]])
 dnl Test for OSS headers
 dnl
